The invention relates to a rock drilling machine comprising at least two blocks joined together with coupling bolts, which drilling machine further comprises a rotating device, a percussion device and a shank, and in which there is provided at least one feed conduit for delivering pressurized lubricant to the shank, the drilling machine being mounted on bearings to be movable with respect to feed equipment.
In mining, rock drill apparatuses are used in which one or more drilling booms are arranged on a platform, the end of each boom being further provided with a feed beam and rock drill. The rock drilling machine comprises a percussion device and a rotating device which are conventionally joined together by means of binding bolts, the entity being then fastened to a separate carriage. The carriage in turn is arranged to be movable with respect to the feed beam and it is moved using feed means arranged to the feed beam. The carriage is usually provided with slide blocks serving as bearing surfaces between the carriage and the guides of the feed beam. The slide blocks are typically made of a bearing metal or plastic material. The slide blocks are usually not lubricated in any way, because they are wearing parts which are changed from time to time. However, slide blocks have been noticed to wear too quickly for example because of impurities that attach on the surfaces of the guides. To prevent the wearing, some manufacturers provide the feed mechanism with means to lubricate the slide surface between the guides and the slide blocks. This arrangement requires, however, a separate lubrication assembly and the related piping to be arranged to the feed beam. This causes extra costs and increased need for servicing. Moreover, a lubrication system arranged to the feed beam is subject to blows and impurities.
It is an object of the present invention to provide a novel arrangement for lubricating the bearing surfaces between a rock drilling machine and feed equipment and to prevent impurities from entering the rock drilling machine structure.
The rock drilling machine of the invention is characterized in that the rock drilling machine comprises at least one return conduit for delivering the lubricant used for lubricating the shank from the shank into at least some of the holes of the coupling bolts, whereby at least some of the spaces surrounding the coupling bolts being pressurized, and that the rock drilling machine further comprises at least one conduit for supplying the lubricant further to lubricate the bearing surface between the rock drill and the feed equipment.
An underlying idea of the invention is that the lubricant used for lubricating the shank is first delivered through conduits formed into the structure of the rock drill into the holes of the coupling bolts connecting the different blocks of the rock drilling machine, the lubricant pressurizing at least some of the coupling bolt spaces. In addition, the lubricant used for lubricating the shank is delivered to a feed mechanism, where it is used for lubricating the bearing surfaces between the feed equipment and the drilling machine.
An essential idea of an embodiment of the invention is that at least some of the coupling bolts are provided with longitudinal conduits in which the lubricant can be carried.
An advantage of the invention is that the lubrication of the bearing surfaces between the rock drill and the feed equipment is carried out using the lubricant leaving the shank, i.e. lubricant already used once, which would otherwise be discharged from the drilling machine into the air. Oil mist led into ambient air produces a gas cloud at the drilling site, thereby causing health risks to those working in the area. Oil mist also spreads far and dirties the drilling equipment and the environment. Because of these drawbacks, also drilling machines provided with separate collecting conduits for recovering the oil mist into a collecting container have been designed. However, the recovery system and its use (emptying and servicing) increase costs. In the present invention, the after-treatment of the lubricant is not a problem or a cause of extra cost, but, on the contrary, the lubricant allows the slide surfaces of the feed equipment to be efficiently lubricated without the need to build a separate lubrication assembly or to add extra lubricant. Moreover, the lubricant, particularly oil mist formed of pressurized air and lubricant, cleans the slide surfaces from impurities, which further reduces the wearing of the feeding devices. Since the oil mist is usually blown to metallic guides having a lower temperature than the oil mist, the oil may be condensed into droplets on the surface of the guides, whereby no significant amounts of oil mist is spread into ambient air. In the invention, the shank lubricant is also used for sealing the spaces of the coupling bolts that join the separate drilling machine blocks together. The oil mist pressurizes the spaces surrounding the coupling bolts, thereby blocking the entry of water, chippings and other impurities into the drilling machine structures through these spaces and thus preventing the wearing of the drilling machine. Further, if the seal between the joint surfaces becomes damaged or if the fastening of the blocks becomes looser over time, or due to any errors in servicing, the lubricant may fill any gaps between the joint surfaces and blows impurities outward.